Slashdot videos: Now with more Slashdot!

View

Discuss

Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

SpuriousLogic writes "US aviation officials are warning air carriers that new research shows lithium batteries are sensitive to heat and can ignite in-flight if transported in cargo compartments that get too hot. The Federal Aviation Administration also acknowledged publicly for the first time Friday that a United Parcel Service 747-400 plane that crashed in Dubai last month killing both pilots was carrying a large quantity of lithium batteries. Since the early 1990s, there have been dozens of incidents of batteries igniting in flight. But it has not been known what triggered many of the fires. FAA now says recent research has identified heat as the trigger and is offering air carriers advice on how to reduce the risk of fire."

Those are not necessarily conflicting ideas... if the temp in the cargo compartment is not controlled, it might be possible for it to get both extremely hot, or extremely cold at times, depending on local weather, whether the plane is on the ground or in flight, etc.

I imagine Lithium isn't the only thing that might catch on fire in extreme heat, however. Many electronic devices have "operating temperature ranges" and "storage temperature ranges"; although I suppose the airline doesn't care much if they break someone's checked iPod or computer due to letting the cargo temp be too extreme -- it's not until risk of fire, that they become more concerned, and think about banning anything containing Lithium batteries in checked luggage, due to the hazard,

How hot are we talking about? The safe maximum operating temperature for discharging a Lithium ion battery is typically 140 degrees Fahrenheit. There's no place on Earth that gets that hot naturally....

The notion that heat in cargo holds might ignite laptop batteries is patently absurd unless the cargo hold is on fire. It's more accurate to say that heat from an actively failing battery can start nearby cells on fire, which is a great big "duh".

Lithium ion battery fires are usually caused by dendritic growth [gizmag.com] inside the cell. There's no good way to determine when this might occur short of scanning electron microscopy, and there is no safe temperature at which this is not a problem....

The only time heat is a factor in Lithium cell failure is typically during a charge cycle (or occasionally during a very fast discharge cycle), when temperatures shoot way up into the mid 100s Fahrenheit. If they go way outside that range, they can go through thermal runaway.

That said, the charge circuits in the battery packs normally make this impossible unless a cell is defective. They shut down in such a way that the pack cannot be charged if the cell voltage drops below a minimum threshold because the charge current required would be high enough to pose a fire risk. Similarly, they disable charging above a maximum threshold to keep the batteries from becoming overcharged.

In short, if these things are burning up in flight, the cells were defective to begin with, period, and odds are good that they were improperly charged, too. There's just no way the cargo hold of an airplane gets hot enough to be a problem unless one of the cells shorts out internally, at which point the temperature really doesn't matter much anyway.

How hot are we talking about? The safe maximum operating temperature for discharging a Lithium ion battery is typically 140 degrees Fahrenheit. There's no place on Earth that gets that hot naturally....

Typically 140 degrees, but this is pretty close to the max temperature for survival of the battery. Just because this temp is in the "operating range" does not mean the temperature is safe, and won't contribute to thermal runaway, where pressure on a cell caused by heat and voltage causes the cell to bu

Iirc, the pressure in the cargo hold is the same as in the passenger cabin. This because it is easier from a engineering point of view as the outer shell can be designed to behave as a pressure vessel.

Valid points. I think cabin pressure is maintained at around 75% of sea level during flight.

And while speculating i guess a takeoff where the cabin pressure was not corrected in time, would cause a rise in temperature (tho the specific math escapes me). If it would be enough to get a cell to initiate thermal runaway i can't say.

"Safe operating values" may not be the same in flight, also: the plane is in motion,

The motion of the contents of a plane relative to the plane itself is likely to be zero

and the cargo hold may be subject to air pressures you don't find naturally anywhere on earth's surface.

Or possibly on some alternate Earth which has no point of it's surface higher than 8,000 feet. What is measured is known as "cabin altitude". If the plane is flying below 8,000 feet then the the cabin altitude is the same as the ac

Or possibly on some alternate Earth which has no point of it's surface higher than 8,000 feet.

Where is this point on the ground on earth that's over 8000ft and experiences temperatures over 100 degrees fahrenheit for long enough periods of time that Lithium Ion battery manufacturers would need to take this into account?

Aircraft aren't designed to be good reflectors of heat; they soak it up, especially UPS birds in brown livery. A big bird sitting on concrete turns into an oven in very short order, and I speak from experience.

According to answers.com [answers.com], the highest natural temperature ever recorded on Earth was a mere 136 degrees Fahrenheit. Also, unless you're on the ground, it's gonna be a lot colder than that. For a cargo hold in flight, I've read that the temperatures typically range between about 30 degrees Fahrenheit and 70 degrees Fahrenheit---in other words, much colder than inside the passenger compartment, not hotter.

How hot are we talking about? The safe maximum operating temperature for discharging a Lithium ion battery is typically 140 degrees Fahrenheit. There's no place on Earth that gets that hot naturally....

Try the inside of a parked car sitting out in the summer sun. The same principle applies to a cargo plane sitting out on the tarmac at an airport in the desert sun.

Try the inside of a parked car sitting out in the summer sun. The same principle applies to a cargo plane sitting out on the tarmac at an airport in the desert sun.

The only part of a plane which has similar amount of glass to a car is the cockpit. There's no separate temperature control for the cockpit, turning the AC on is going to cool the whole plane.Dosn't look like Boeing fits that many windows if you order a freighter. Not like cargo tends to worry about the view:) Indeed the only one on the main d

Besides, planes aren't made of glass, and this is talking about fires during flight, not on the ground. Most of the time, they're flying at 30,000 feet or so, where the ambient air temperature is well into the negative double digits (like fifty or sixty degrees below zero Fahrenheit).... The only way I can think of that they could get to 140 degrees would be if they did something insane

In short, if these things are burning up in flight, the cells were defective to begin with, period, and odds are good that they were improperly charged, too. There's just no way the cargo hold of an airplane gets hot enough to be a problem unless one of the cells shorts out internally, at which point the temperature really doesn't matter much anyway.

Do lithium batteries discharge over time on their own? Because if they do, and generate some heat while doing it, then all you have to do is pack enough of the

The self-discharge on Li-ion and Li-poly batteries is generally too slow to generate significant heat. The self-discharge rate as well as discharge cycle waste heat from them are significantly lower than other battery types, such as NiMH/NiCd or Lead Acid

One of the really nice things about Li-ion and Li-polymer batteries in the applications that I'm familiar with - radio control cars - is that even under pretty high loads they don't heat up. It's only when you get to loads in the 50-100C (Call it about 1kW

How hot are we talking about? The safe maximum operating temperature for discharging a Lithium ion battery is typically 140 degrees Fahrenheit. There's no place on Earth that gets that hot naturally....

remember too, that the cargo hold may be unpressurized... which means at 35,000 feet the Lithium-ion batteries are going to leak hydrogen causing more of a fire hazard as they're usually not rated for operation above 10,000 feet and the chemical reactions go all wonky.

Also, are you sure about the hydrogen thing? I know lead acid and NiMH batteries vent hydrogen, and some lithium ion batteries vent HCN (hydrogen cyanide), which burns pretty easily, but I couldn't find anything about any of them venting hydrogen....

Don't think "too hot" or "too cold" exclusively. Think "poorly controlled temperature and ventilation". A cargo hold can be too hot, too cold, have too little air circulation for pets, and apparently can be hot enough to cause cargo that would be safe in the cabin into a crash hazard.

Also remember that with delays planes are often on the tarmac or taxiway for hours at a time in the sun with the checked baggage on them but no people. I doubt they're going to air condition the holds in case your laptop is on

it depends on which cargo hold your stuff is put in on an airplane. On my aircraft, the forward hold is heated & pressurized, and the aft hold is not.

here's how the bins (as we call them) are pressurized/heated. the air that comes out of the packs is routed through the cabin, then flows through the cargo bin before being dumped overboard through the pressurization valve. so while the bin is heated, there is no direct control of the heat like the cabin. we have charts in our manuals that will tell us the temp of the bins based on the outside air temp, so we can tell whether or not its safe to put Fido in the cargo, but otherwise we have no direct way of monitoring the cargo compartment temp.

While I don't doubt you know what you are talking about, how exactly can air that has been used to heat/cool the passenger compartment, which must be kept around 20 degrees C, suddenly become much hotter when it reaches the pressurized hold? Unless this air is passing through a compressor of some kind that really jacks up the pressure resulting in heat, there is no way that the air arriving to the hold is going to be that hot after coming from the passenger compartment. If anything the outside temp while at

I know that, during the summer, Delta Air Lines will have pet embargoes to and from certain destinations because of the heat as well. It's not necessarily the temperature in the air or at the destination either, although that is a factor. Remember, cargo is loaded as early as an hour before departure. Temperatures outside on the ramp in Atlanta can reach well over 100. Inside a cargo compartment it can get even worse.

as Nidi says, it can get really hot on the ramp. i know when its hot out and we've shut down the APU, the empty airplane goes from a comfortable 75 to almost 90 in about 15 minutes. that's with the doors open. if they load the cargo early & close the door, there is no airflow whatsoever in there until we turn on the packs.

In a place like Dubai the airport is probably pretty busy and it's very hot on the ground. It gets hot enough in the cabin sometimes when you're stuck sitting on the runway for a while, and I'm sure the cargo compartment probably heats up pretty good too.

Of course when the plane is at cruising altitude the air around the plane is incredibly cold and the cargo compartment would be too if it's not heated...

Funnily enough mine did in Adelaide about four years ago. Waiting for the plane the airline announced a hold. They had to change a wheel apparently but I watched the plane and no wheels where touched. On arrival in Melbourne the laptop was warm and the battery was totally flat. My guess is that security left it running because they didn't know how to shut down mandrake.

I've never been to Australia, but in the US a flight number and a particular aircraft have only a very loose connection to one another. I've had flights delayed while "our" plane was used to carry some other flight with more passengers or which could still be made on time while "their" plane was fixed in the hangar and then used for my flight. I've seen flights outright cancelled, and they'll cancel the flight that causes the least hassle to cancel and announce for some other flight's passengers to board at

Any idiot who checks a laptop is begging to have it stolen, broken, or both.

Or simply chooses not to live constantly on the defensive. Yes, sometimes bad things happen, but It's much nicer in the long run to just do the things you want to rather than constantly sacrifice ease and convenience for fear of losing an item or two.

That's a good philosophy, but it only works as long as you prevent the occassional incident from being a catastrophe. A laptop is just expensive, the data on it with no back up might be priceless...

*shrugs* Data on it with no backup WILL be lost eventually -- and most highly volatile or new data can be reconstructed. Shit happens, you deal with it, and that's life. (and yes, I HAVE had my laptop stolen (and felt pretty violated for a while), though not in an airport, and this is still my philosophy.)

I guess you must have relatives that sell laptops, with advice like that.

It's not being "defensive" to think that a delicate electronic device held within a flimsy container that will by the very nature of luggage be battered, and almost unprotected from thievery come to harm. It's simply being realistic.

Plus who doesn't want a laptop with them when traveling? What good is it doing you in the hold?

If you check a laptop, there is a significant chance it's not making it to your destination in working order, or even at all. Baggage handlers are not gentle, and theft is rampant. It's not like terrorism where people are all worked up over something that has an almost zero chance of occurring.

If you check a laptop, there is a significant chance it's not making it to your destination in working order, or even at all.

I frequently make long international flights involving two plane changes. I used to carry my laptop and use it during the layovers. Once I got an iPad I no longer had a specific need to use the laptop during that time, but still needed to take it with me on the trip. It's annoying to lug around, especially during those long hurried walks to get to the next gate, and so I decided to

Spare batteries? Yes, I could see them not letting you bring them along. But the laptop itself? Never had a problem. Even have a laptop bag that doubles as a purse and is both big enough to actually carry useful stuff, but small enough to pass carry-on rules, and never had issues with it.

Come to think of it, I've never had an airline count my laptop bag in the carry-on, specifically because they didn't want to take responsibility for it if it was checked. And yes, I have flown recently.

Spare batteries? Yes, I could see them not letting you bring them along. But the laptop itself? Never had a problem. Even have a laptop bag that doubles as a purse and is both big enough to actually carry useful stuff, but small enough to pass carry-on rules, and never had issues with it.

Yep, It's the spare batteries they object to, each time, not the laptop:( That's a bummer when i'm on a 1 stop flight from Patna to Mumbai, and can use the lappy only for the first leg.

Come to think of it, I've never had an airline count my laptop bag in the carry-on, specifically because they didn't want to take responsibility for it if it was checked. And yes, I have flown recently.

In India, You are allowed 1 Carry on Case, 1 other piece of luggage, including a coat-bag, valise or briefcase OR laptop bag, and in addition, a reasonable amount of reading material. I usually travel with my hands full:)

Wow, so apparently TFS == TFA (which in turn is nothing but a copypasta of an AP release [google.com] from earlier today. Is there really no more information on this? For example, how hot is too hot? My laptop gets pretty freaking hot sometimes and I'd guess a fair bit of that heat finds its way into the battery.

Kind of interesting. It looks like I probably don't need to worry about my laptop's head igniting the battery, but it does sound like either some batteries are a lot more susceptible to heat, or airplane cargo compartments get really hot. I would guess a lot of other stuff doesn't like being stored at those kinds of temperatures either. A quick look indicates most plastics melt at about 300-450 degrees F [machinist-materials.com]. In fact, ABS plastic (usually used in laptop battery enclosures) melts even lower at 221 degrees F [dynalabcorp.com].

Yeah, this is why I was confused by this report. Lithium-ion cells have to get VERY hot in order to vent, and even then, they have multiple safety systems that attempt to prevent failures that could start a fire. If cargo compartments were getting hot enough to set cells off there would be complaints about many other things melting first. I would be surprised if the cargo compartments even reach 60 Celsius (140 F) which are within the operating bounds of lithium-ion cells (though at seriously reduced per

TFA is bullshit. The FAA report says that lithium batteries pose a hazard if heated by a fire from another material in the cargo hold. I guess "Heat in Cargo Holds Can Ignite Laptop Batteries" is accurate if you just forget to mention that the heat the FAA is talking about is coming from flames. See my other comment for a link to the actual report.

The only reason I could possibly see a higher incidence of cell explosion when on aircraft is if the cell was in a non-pressurized compartment such that the sealed cell expanded in such a way that an internal short was caused in the cell causing a fire.

Ah yes, pV=nRT. Of course, increasing temperature while simultaneously reducing air pressure is a neat trick in an airplane unless you're on a tarmac in Denver. Even then it doesn't seem like enough.

Yeah, this is why I was confused by this report. Lithium-ion cells have to get VERY hot in order to vent, and even then, they have multiple safety systems that attempt to prevent failures that could start a fire. If cargo compartments were getting hot enough to set cells off there would be complaints about many other things melting first. I would be surprised if the cargo compartments even reach 60 Celsius (140 F) which are within the operating bounds of lithium-ion cells (though at seriously reduced perfor

Several months ago, on a flight from Virginia to California, a zip-lock bag containing spare batteries for my phone and camera and several power&usb cables "disappeared" from my luggage. At first I thought I had left it behind, but that turned out not to be the case. A couple of months later, I had a nearly identical zip-lock bag in my carry-on (sans the camera battery, which I have not yet replaced). I was pulled aside for "extra scrutiny" specifically because of this bag. The TSA agent removed it, re-ran my luggage, and returned it to me. I can only deduce that the TSA "stole" my batteries and cables on the earlier journey, because nothing looks more like a bomb that a Nokia cell phone battery and a USB cable.

A couple of months later, I had a nearly identical zip-lock bag in my carry-on (sans the camera battery, which I have not yet replaced). I was pulled aside for "extra scrutiny" specifically because of this bag.

I typically travel with more cables, chargers, and batteries than you can shake a stick at (Two cameras, an iPhone, a laptop, a hiking GPS and an Nuvi.) I've never been pulled for extra scrutiny - except the one time I was headed home for a funeral and had only my cell phone and laptop. I.E. don't t

+1 - I fly with a ridiculous assortment of cables and spare batteries as well (2-3 cameras with two extra batteries each, two cell phones with extra batteries, a laptop, a sony e-reader, sometimes a hiking gps, all of the chargers and cables that go with those things, and other stuff I'm probably forgetting), I fly quite frequently, and I never have a problem. I used to sometimes get extra scrutiny and hand-searches of my DSLR lenses, but those must be getting a lot more familiar to the TSA recently because

Interesting. I thought the TSA were required by law to put a notice in your luggage if they open it for extra inspection, let along removing something without permission and not notifying you. I know that I have sometimes found these notices in my checked bags. Basically it tells you the TSA searched your bag, what your rights are, who to contact if you have questions on the inspection, etc.

I have a real problem that the TSA, or anyone else for that matter, would have carte blanche to search bags and remove

Smells like a thief stole you stuff, regardless if he/she was working for TSA or not.

Airports always tell you never to leave your baggage unattended. If a TSA employee stole your stuff, it's the TSA's fault. If the TSA left your baggage unattended and another thief stole your stuff, it's the TSA's fault. This is a security issue - if a rogue employee can get away with taking stuff from your luggage, they can put whatever they want *in* your luggage too.

When I travel, I don't use TSA locks. I don't use locks at all. I tie the clasp with mason line and apply a folded over mailing label over the knot with my name and photo on it along with "Packed and sealed by owner" printed on it. I carry extra string and seals in my shirt pocket for the occasional bag inspection at the xray. To date, I have never had a bag missing the seal at my destination.

Basically what this says is, a fire in a cargo compartment could easily heat lithium batteries to the point that they cause explosions and large secondary fires. Also, the fire suppressant commonly used in cargo bays may not control a lithium fire. Thirdly, shorted lithium batteries may get so hot that they ignite other materials around them, even if they don't catch fire themselves. Lithium-Ion batteries are also mentioned, basically restating the above but suggesting that existing fire suppression can more easily control a fire from a lithium-ion cell.

In the end, the recommendation is to change reporting rules so that lithium batteries in cargo must be reported to the pilot in command. Effort should be made to carry them in cargo bays with sufficient fire extinguisher capability. Also mentioned is storing them in containers designed to keep fire or explosion contained, and that existing containers will not do this.

It is even specifically noted that this advisory applies to bulk shipments and does not include batteries brought aboard by passengers.

Metal Lithium batteries!=Lithium-Ion batteries used in laptops. Metal Lithium batteries are too dangerous to be used in laptops.

Metal lithium batteries are a Class 9 Miscellaneous Dangerous Good as well as Cargo Aircraft Only. As such they must be on the NOTOC (notice to captain) and cannot be on passenger aircraft.Lithium ion batteries are also Class 9 Miscellaneous, but depending on the size of the battery, number of batteries per individual box, packaging and so on can either be classified as being an excepted quantity (meaning they are not listed on the NOTOC) or they will show up on the NOTOC.

Faulty logic. Provide power to each seat and passengers will put their spare batteries in checked luggage. In the cargo hold. No seat power means they have to carry their spares on with them, keeping them in conditioned air.

I can see your point. My uncle used to fly for various airlines. In one country where some people routinely carried guns there was a special box on board for weapons. The captain had the key. Maybe there should be special storage for certain types of energy storage devices. Not just batteries. OF course if that box goes up...

Batteries are safer in carry on luggage than in checked luggage. No special box needed. If a briefcase or backpack starts smoking while under a seat or in an overhead bin, it will be seen (smelled). If it catches fire buried in checked luggage, it will be a while before the temperature rise triggers extinguishers. And then what? Its still buried in the luggage. In the cabin, you can toss it in the galley oven and let it smoke.

http://en.wikipedia.org/wiki/South_African_Airways_Flight_295 [wikipedia.org]
A South African commercial flight (Flight 295/The Helderberg) suffered a catastrophic in-flight fire in the cargo area and crashed into the Indian Ocean.
Parts recovery from the Boeing 747-244B Combi was at a depth of 4,900 metres (16,100 ft).
What caused the hot fire was never really exposed even after the change of government.
South Africa might have needed exotic at the time new air defence devices ie new/parts for High Speed Anti-Radiation Missiles?

Thats pretty, bad although I highly doubt it could really get that hot during flight. I never heard of people complaining of molten stuff.
More importantly... In a way we are really afraid of terrorists (this is bs to me) but then they publicly announce, weaknesses in current security, since heat wont but a short can easily cause this.... I don't understand...

Makes you keep your laptop in your hands, easy to spot a person of interest in a line.
vs. profile data and a bag opened pre flight as a best guess.
Can put your face and "personality" with the laptop and any data can be cloned after been pulled aside for a chat.
Less a weaknesses I guess, more a 'crisis' to allow for better data mining?

The distinction between Lithium Ion and Lithium Metal batteries is by no means made clear in the FAA report. [faa.gov] After reading through it, I have to disagree with others who suggest that this doesn't affect laptop batteries. It does.

Sorry, there may well be, (somewhere) a few government workers who have not been driven insane through the repeated need to exist in an increasingly cognitively dissonant state, but it's a solid bet that they are few and far between. Not counting those who are outright sociopaths, of course.

ANY advisory coming from the government is liable to be false, spin, or otherwise manipulative in nature. In this case, I think, it's probably a set-up for future controls.

It should also be noted that batteries on their own can't burst into flame due to environmental heating in a cargo bay. (It's COLD up there at 10,000 feet!) The FAA report was only talking about batteries catching alight in an already existing fire.

But that's not the way the media story tracked. Everybody assumed batteries burst into flame of their own volition. Public impression and emotional reactions are far more important than facts today. No doubt the idea of over-charged batteries bursting into flame will be floated by alarmists.

Just another way to put the squeeze on travelers. International travel will soon require that you navigate several paradoxical gauntlets just to get seated. Best to just stay at home where you won't see what the outside world is really like.

Fascist nations never like their people to travel. This is the same thing, with one subtle difference; they're trying to sneak it by as a series of rational measures we all voluntarily agree with rather than force it upon us overtly.

No doubt the idea of over-charged batteries bursting into flame will be floated by alarmists.

FUD FUD FUD. No doubt the fear of over-reaction by the media will cause conspiracy theorists on internet boards to twist this to try and support their pet theory. The recommendations specifically cover bulk shipments on cargo carriers, not personal laptops from travelers on commercial flights. That is an important distinction. The former makes this a (nearly) no-brainer, and good work by the FAA. The latter interpretation of the headlines make this a great article to get everyone up in arms. Like it seems t

Would somebody mark the parent as a troll? Dismissing an advisory on _bulk_ Lithium transports with "ZOMG THE GUVMENTS IS TAKING MY RIUTS!" is no better than "ZOMG THINK OF THE CHILDREN".

You think an industry which, based on stupid thinking, will no longer allow you to carry bottled water onto a flight is sane enough to not flip out over batteries which do in fact explode from time to time?

Or are you one of those people Socrates would have easily convinced of patently ridiculous things simply because each step toward madness seemed reasonable?

We have plenty of evidence of crazy government behavior. PLENTY of it. I don't trust government officials to be smart or rational. Do you?